Blade positioning system for motor grader

ABSTRACT

A positioning system for a blade associated with a drawbar-circle-moldboard of a motor grader is disclosed. The positioning system may include a cylinder connecting the blade to the drawbar-circle-moldboard and configured to affect movement of the blade relative to the drawbar-circle-moldboard, and a sensor configured to generate a signal indicative of a current position of the blade. The positioning system may include an input device having a button configured to receive a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions, and receive a second operator input indicative of a selection of one of the plurality of predefined blade positions. The positioning system may further include a controller configured to selectively actuate the cylinder based on the selection and the signal.

TECHNICAL FIELD

The present disclosure is directed to a blade positioning system, and more particularly, to a blade positioning system for a motor grader.

BACKGROUND

Motor graders are used primarily as finishing tools to sculpt a surface of a construction site to a final shape and contour. Typically, motor graders include many hand-operated controls to steer the wheels of the grader, position a blade, and articulate the front frame of the grader. The blade is adjustably mounted to the front frame to move relatively small quantities of earth from side to side. In addition, the articulation of the front frame is adjusted by rotating the front frame of the grader relative to the rear frame of the grader.

To produce a final surface contour, the blade and the frame may be adjusted to many different positions. Positioning the blade of a motor grader can be a complex and time-consuming task. In particular, operations such as, for example, controlling surface elevations, angles, and cut depths may require a significant portion of the operator's attention. Such demands placed on the operator may cause other tasks necessary for the operation of the motor grader to be neglected.

One way to simplify operator control is to allow the operator to recall an input stored in a memory associated with a control device. One example of such a memory control is disclosed in U.S. Pat. No. 7,729,835 issued to Morris et al. on Jun. 1, 2010 (the '835 patent). In particular, the '835 patent discloses an excavator having a working implement and hydraulic actuators that allow the working implement to be raised, lowered, and moved closer to or further from a body of the excavator. The excavator is equipped with a first joystick having a thumbwheel control and a second joystick having a function selection switch and a memory control. The function selection switch allows an operator to select from multiple operating functions. The thumbwheel allows the operator to control the selected operating function. The memory control allows an input by the operator to be memorized and recalled at a later time. The input is memorized until the memory control is deactivated or a new input is memorized by the memory control.

Although the system of the '835 patent may simplify operator control in some applications, it may still be less than optimal. In particular, the memory control of the '835 patent allows only a single input to be memorized at a time. Indeed, when a new input is memorized, the previous input is overwritten, which prevents the operator from recalling multiple inputs. In addition, the memory control of the '835 patent has multiple controls that each provide a different function. Having too many controls can increase complexity and the required space on the joysticks.

The disclosed system of the present disclosure solves one or more of the problems set forth above and/or other problems in the art.

SUMMARY

In one aspect, the present disclosure is directed to a positioning system for a blade associated with a drawbar-circle-moldboard of a motor grader. The positioning system may include a cylinder connecting the blade to the drawbar-circle-moldboard and configured to affect movement of the blade relative to the drawbar-circle-moldboard, and a sensor configured to generate a signal indicative of a current position of the blade. The positioning system may include an input device having a button configured to receive a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions, and receive a second operator input indicative of a selection of one of the plurality of predefined blade positions. The positioning system may further include a controller configured to selectively actuate the cylinder based on the selection and the signal.

In another aspect, the present disclosure is directed to a method for positioning a blade associated with a drawbar-circle-moldboard of a motor grader. The method may include sensing a current position of the blade. The method may also include receiving a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions via a button, and receiving a second operator input indicative of a selection of one of the plurality of predefined blade positions via the same button. The method may further include selectively actuating a cylinder to affect movement of the blade relative to the drawbar-circle-moldboard based on the selection and the current position of the blade.

In yet another aspect, the present disclosure is directed to a motor grader. The motor grader may include a power source, at least one traction device, a frame, a drawbar-circle-moldboard supported by the frame, and a blade pivotally connectable to the drawbar-circle-moldboard. The motor grader may also include a cylinder connecting the blade to the drawbar-circle-moldboard and configured to affect movement of the blade relative to the drawbar-circle-moldboard, and a sensor configured to generate a signal indicative of a current position of the blade. The motor grader may further include a joystick. The joystick may have a first button configured to receive a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions, and receive a second operator input indicative of a selection of one of the plurality of predefined blade positions. The joystick may also have a second button configured to receive a third operator input indicative of a desire to cause the cylinder to move the blade to a selected blade position corresponding with the selection. The motor grader may further include a controller configured to selectively actuate the cylinder based on the first, second, and third operator inputs and the signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a pictorial illustration of an exemplary disclosed motor grader;

FIG. 2 is a schematic illustration of an exemplary disclosed blade positioning system that may be used in conjunction with the motor grader of FIG. 1; and

FIG. 3 is a flowchart depicting an exemplary disclosed method that may be performed by the blade positioning system of FIG. 2.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary machine 10. In the disclosed embodiment, machine 10 may embody a motor grader. However, in other embodiments, machine 10 may embody an excavator, a backhoe loader, an agricultural tractor, a wheel loader, a skid-steer loader, or any other type of machine known in the art. Machine 10 may include a steerable traction device 12, a driven traction device 14, a power source 16 supported by driven traction device 14, and a frame 18 connecting steerable traction device 12 to driven traction device 14. Machine 10 may also include a work implement such as, for example, a drawbar-circle-moldboard assembly (DCM) 20, an operator station 22, and a blade positioning system 24.

Both steerable and driven traction devices 12, 14 may include one or more wheels located on each side of machine 10 (only one side shown). The wheels may be rotatable and/or tiltable for use during steering and leveling of a work surface (not shown). Alternatively, steerable and/or driven traction devices 12, 14 may include tracks, belts, or other traction devices known in the art. It is contemplated that, in some embodiments, steerable traction devices 12 may also be driven, while driven traction device 14 may also be steerable. Frame 18 may connect steerable traction device 12 to driven traction device 14 by way of, for example, an articulation joint 26. Furthermore, machine 10 may be caused to articulate steerable traction device 12 relative to driven traction device 14 via articulation joint 26.

Power source 16 may include an engine (not shown) connected to a transmission (not shown). The engine may be, for example, a diesel engine, a gasoline engine, a natural gas engine, or any other engine known in the art. Power source 16 may also be a non-combustion source of power such as a fuel cell, a power storage device, or another source of power known in the art. The transmission may be an electric transmission, a hydraulic transmission, a mechanical transmission, or any other transmission known in the art. The transmission may be operable to produce multiple output speed ratios and may be configured to transfer power from power source 16 to driven traction device 14 at a range of output speeds.

Frame 18 may include an articulation joint 26 that connects driven traction device 14 to frame 18. Machine 10 may be caused to articulate steerable traction device 12 relative to driven traction device 14 via articulation joint 26. Machine 10 may also include a neutral articulation feature that, when activated, causes automatic realignment of steerable traction device 12 relative to driven traction device 14 to cause articulation joint 26 to return to a neutral articulation position.

Frame 18 may also include a beam member 28 that supports a fixedly connected center shift mounting member 30. Beam member 28 may be, for example, a single formed or assembled beam having a substantially hollow square cross-section. The substantially hollow square cross-section may provide frame 18 with a substantially high moment of inertia required to adequately support DCM 20 and center shift mounting member 30. The cross-section of beam member 28 may alternatively be rectangular, round, triangular, or any other appropriate shape.

Center shift mounting member 30 may support a pair of double acting hydraulic rams 32 (only one shown) for affecting vertical movement of DCM 20, a center shift cylinder 34 for affecting horizontal movement of DCM 20, and a link bar 36 adjustable between a plurality of positions. Center shift mounting member 30 may be welded or otherwise fixedly connected to beam member 28 to indirectly support hydraulic rams 32 by way of a pair of bell cranks 38, also known as lift arms. That is, bell cranks 38 may be pivotally connected to center shift mounting member 30 along a horizontal axis 40, while hydraulic rams 32 may be pivotally connected to bell cranks 38 along a vertical axis 42. Each bell crank 38 may further be pivotally connected to link bar 36 along a horizontal axis 44. Center shift cylinder 34 may be similarly pivotally connected to link bar 36.

DCM 20 may include a drawbar member 46 supported by beam member 28 and a ball and socket joint (not shown) located proximal steerable traction device 12. As hydraulic rams 32 and/or center shift cylinder 34 are actuated, DCM 20 may pivot about the ball and socket joint. A circle assembly 48 may be connected to drawbar member 46 via a motor (not shown) to drivingly support a moldboard assembly 50 having a blade 52 and blade positioning cylinders 54. In addition to DCM 20 being both vertically and horizontally positioned relative to beam member 28, DCM 20 may also be controlled to rotate circle and moldboard assemblies 48, 50 relative to drawbar member 46. Blade 52 may be moveable both horizontally and vertically, and oriented relative to circle assembly 48 via blade positioning cylinders 54.

Operator station 22 may embody an area of machine 10 configured to house an operator. Operator station 22 may include a dashboard 56 and an instrument panel 58 containing dials and/or controls for conveying information and for operating machine 10 and its various components.

As shown in FIG. 2, dashboard 56 may include a display system 60, and instrumental panel 58 may include a user interface 62. Display system 60 and user interface 62 may be in communication with blade positioning system 24. Display system 60 may include a computer monitor with an audio speaker, video screen, and/or any other suitable visual display device that conveys information to the operator. For example, in one embodiment, display system 60 may be configured to display a plurality of predefined blade positions and illustrate a selection of one of the plurality of predefined blade positions. User interface 62 may include a keyboard, a touch screen, a number pad, a joystick, or any other suitable input device. In the disclosed embodiment, user interface 62 embodies a joystick.

Blade positioning system 24 may move blade 52 to a predetermined position in response to input signals received from user interface 62. Blade positioning system 24 may include one or more sensors 64 and a controller 66. Sensors 64 may include, for example, cylinder position sensors, an articulation sensor, a link bar sensor, and/or a grade detector. It is contemplated that blade positioning system may include other sensors known in the art, if desired. The cylinder position sensors may sense the extension and retraction of hydraulic rams 32, center shift cylinder 34, and/or blade positioning cylinders 54. The articulation sensor may sense the movement and relative position of articulation joint 26 and may be operatively coupled with articulation joint 26. The link bar sensor may sense the rotational angle of bell cranks 38 about horizontal axis 40. The grade detector may be a dual axis inclinometer associated with machine 10 and may continuously detect an inclination of machine 10 with respect to true horizontal. It should be understood that the extension and retraction of the cylinders and/or the movement of articulation joint 26 may be compared with reference look-up maps and/or tables stored in the memory of controller 66 to determine the position and orientation of blade 52 and/or the articulation of joint 26.

In one embodiment, sensors 64 may provide signals indicative of a cross-slope inclination of blade 52. The cross-slope inclination of blade 52 may defined as an inclination in a direction transverse to a path (“cross-slope”) along which machine 10 travels. In some embodiments, the cross-slope inclination of blade 52 may be represented as a percentage, while, in other embodiments, the cross-slope inclination of blade 52 may be represented as an angle.

As shown in FIG. 2, user interface 62 may include one or more buttons configured to receive operator input indicative of one or more desired blade operations. For example, user interface 62 may include a first button 68, a second button 70, and a third button 72. First button 68 may be configured to receive operator input indicative of a desire to store a target position of blade 52 as one of a plurality of predefined blade positions stored in a memory of controller 66. In addition, first button 68 may also be configured to receive operator input indicative of a selection of one of the plurality of predefined blade positions. Second button 70 may be configured to receive operator input indicative of a desire to cause the extension and retraction of hydraulic rams 32, center shift cylinder 34, and/or blade positioning cylinders 54 to move blade 52 to a corresponding selected blade position. It should be noted that hydraulic rams 32, center shift cylinder 34, and/or blade positioning cylinders 54 may not be actuated to move blade 52 to a desired position and orientation, until second button 70 has been engaged (i.e., engaging first button 68 alone will not cause movement of blade 52). Third button 72 may be configured to receive operator input indicative of a predetermined incremental adjustment of the position of blade 52. For example, the predetermined incremental adjustment of the position of blade 52 may be an increase or a decrease in a predetermined percentage or angle of cross-slope inclination of blade 52.

In the disclosed embodiment, first, second, and third buttons 68, 70, 72 are positioned on user interface 62 in a manner to facilitate the operator's access to each button. In particular, as shown in FIG. 2, all three buttons may be grouped together, such that a single finger of the operator can reach each button without requiring significant movement of the operator's hand. The close proximity of all three buttons on user interface 62 may improve ergonomics and operator comfortability as well as reduce a response time by the operator.

Controller 66 may embody a single microprocessor or multiple microprocessors configured to actuate hydraulic rams 32, center shift cylinder 34, and/or blade positioning cylinders 54 to move blade 52 to a desired position and orientation based on received operator input. Numerous commercially available microprocessors can be configured to perform the functions of controller 66. It should be appreciated that controller 66 could readily embody a general machine microprocessor capable of controlling numerous machine functions. Controller 66 may include a memory, a secondary storage device, a processor, and any other components for running an application. In the disclosed embodiment, the memory may store the plurality of predefined blade positions. Various other circuits may be associated with controller 66 such as power supply circuitry, signal conditioning circuitry, solenoid driver circuitry, and other types of circuitry.

In some embodiments, controller 66 may be configured to store or select a target position of blade 52 in response to a predetermined threshold associated with the operator's interaction with user interface 62. For example, if first button 68 is engaged by the operator for a predetermined period of time, controller 66 may store the target position of blade 52 as one of the plurality of predefined blade positions. However, if first button 68 is engaged by the operator for less than the predetermined period of time, controller 66 may instead select one of the plurality of predefined blade positions.

FIG. 3 is a flowchart depicting an exemplary disclosed method 300 that may be performed by the system of FIGS. 1 and 2. FIG. 3 will be discussed in more detail below to further illustrate the disclosed concepts.

INDUSTRIAL APPLICABILITY

The disclosed system may be implemented into any machine operation requiring automated control of a work implement. The disclosed system may simplify operator control by allowing the operator to select and store a plurality of predefined blade positions in a memory. In addition, the disclosed system may implement multiple functions into a single button, thereby further simplifying operator control. Furthermore, the disclosed system may delay movement of the blade until the operator indicates a desired to move the blade to a selected position. The operation of blade positioning system 24 will now be explained.

Referring to FIG. 3, the method may begin by receiving one or more operator inputs via user interface 62 (e.g., joystick) at step 302. For example, the operator may engage one or more of first button 68, second button 70, and third button 72, causing signals to be transmitted to controller 66. Controller 66 may receive and process the signals to determine a blade operation based on the received operator input.

At step 304, controller 66 may determine whether first button 68 is engaged based on the received operator input. If first button 68 is engaged, then the method may proceed to step 306. Otherwise, the method may return to step 302 to receive more operator inputs.

At step 306, controller 66 may determine whether a predetermined threshold associated with first button 68 has been exceeded. For example, controller 66 may determine whether first button 68 has been engaged for greater than a predetermined period of time (e.g., two seconds). If the operator engages first button 68 for greater than two seconds, then the method may proceed to step 308. If the operator engages the first button 68 for less than two seconds, however, the method may proceed to step 310.

At step 308, after first button 68 has been engaged for greater than two seconds, controller 66 may store a target position of blade 52. For example, the operator may engage third button 72 to manually adjust the target position of blade 52 to a desired blade position. Controller 66 may then store the target position in the memory of controller 66 after first button 68 has been engaged for greater than two seconds. In one example, if first button 68 is engaged for greater than two seconds, and the target position of blade 52 is 25% cross-slope inclination, then, 25% cross-slope inclination may be stored as a predefined blade position. It should be noted that, in some instances, the target position of blade 52 may be different from a current position of blade 52. In one example, the current position of blade 52 may be 15% cross-slope inclination. The operator may then engage third button 72 to manually adjust the target position of blade 52 to 25% cross-slope inclination, while the current position of blade 52 remains at 15% cross-slope inclination. Thereafter, the operator may engage first button 68 for greater than two seconds to store the target position of blade 52 (25% cross-slope inclination), again while the current position of blade 52 remains at 15% cross-slope inclination. After step 308, the method may return to step 302 to receive more operator inputs.

At step 310, after first button 68 has been engaged for less than two seconds, controller 66 may select one of the predefined blade positions stored in the memory of controller 66. As discussed in step 308, the operator may have previously stored one or more blade positions. The process at step 310 allows the operator to recall and scroll through the predefined blade positions until the desired predefined blade position is selected. For instance, first, second, and third predefined blade position of 8%, 25%, and 12%, respectively, may be stored in the memory of controller 66. By engaging first button 68 for less than two seconds one time, the first predefined blade position of 8% cross-slope inclination may be selected. Then, by engaging first button 68 for less than two seconds a second time, the second predefined blade position of 25% cross-slope inclination may be selected. By engaging first button 68 for less than two seconds a third time, the third predefined blade position of 12% cross-slope inclination may be selected. Finally, by engaging first button 68 for less than two seconds a fourth time, the selection may return to the first predefined blade position of 8% cross-slope inclination. It is contemplated that any number of predefined blade positions may be stored in the memory of controller 66, as desired. After step 310, the method may proceed to step 312.

At step 312, controller 66 may determine whether second button 70 has been engaged based on the received operator input. If second button 70 is engaged, then the method may proceed to step 314. Otherwise, the method may return to step 302 to receive more operator inputs.

At step 314, controller 66 may send signals to actuate hydraulic rams 32, center shift cylinder 34, and/or blade positioning cylinders 54 to move blade 52 to a corresponding selected blade position. For example, controller 66 may receive signals from sensors 64 to determine the current position of blade 52 and, then, move blade 52 to a corresponding selected blade position based on the current position of blade 52. Until second button 70 is engaged, controller 66 may not cause movement of blade 52. This may provide a safety feature, such that blade 52 does not move to an undesired position. For example, using the above example, if the first, second, and third predefined blade position are 8%, 25%, and 12% cross-slope inclination, respectively, the operator must switch from 8% cross-slope inclination to 25% cross-slope inclination, and then to 12% cross-slope inclination. If engaging first button 68 alone was enough to cause movement of blade 52, then, blade 52 would start moving to 25% cross-slope inclination before the operator selected 12% cross-slope inclination. This can lead to undesirable consequences, such as, the blade removing more of a work surface than desired. The use of second button 70 may delay movement of blade 52 until the operator indicates a desire to move the blade, thereby preventing undesirable movements of blade 52.

By implementing the disclosed method, operator control may be simplified. Specifically, providing a single button with multiple functions may reduce complexity. In addition, storing a plurality of predefined blade positions may provide more autonomous control to assist the operator. Finally, delaying the movement of the blade to a selected blade position until the operator indicates a desired to move the blade can reduce errors associated with undesired movements of the blade.

It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents. 

What is claimed is:
 1. A positioning system for a blade associated with a drawbar-circle-moldboard of a motor grader, comprising: a cylinder connecting the blade to the drawbar-circle-moldboard and configured to affect movement of the blade relative to the drawbar-circle-moldboard; a sensor configured to generate a signal indicative of a current position of the blade; an input device having a button configured to: receive a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions; and receive a second operator input indicative of a selection of one of the plurality of predefined blade positions; and a controller configured to selectively actuate the cylinder based on the selection and the signal.
 2. The positioning system of claim 1, further including a display configured to display the plurality of predefined blade positions and illustrate the selection of one of the plurality of predefined blade positions.
 3. The positioning system of claim 1, wherein the position of the blade includes a cross-slope inclination.
 4. The positioning system of claim 1, wherein the input device includes a joystick.
 5. The positioning system of claim 1, wherein: the button is a first button; and the input device has a second button configured to receive a third operator input indicative of a desire to cause the cylinder to move the blade to a corresponding selected blade position.
 6. The positioning system of claim 5, wherein the controller is configured to store the target position of the blade as one of the plurality of predefined blade positions when the first button is engaged for a predetermined period of time.
 7. The positioning system of claim 6, wherein the controller is configured to select one of the plurality of predefined blade positions when the first button is engaged for less than the predetermined period of time.
 8. The positioning system of claim 5, wherein the input device has a third button configured to receive a fourth operator input indicative of a predetermined incremental adjustment of the position of the blade.
 9. A method for positioning a blade associated with a drawbar-circle-moldboard of a motor grader, comprising: sensing a current position of the blade; receiving a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions via a button; receiving a second operator input indicative of a selection of one of the plurality of predefined blade positions via the same button; and selectively actuating a cylinder to affect movement of the blade relative to the drawbar-circle-moldboard based on the selection and the current position of the blade.
 10. The method of claim 9, further including displaying the plurality of predefined blade positions and the selection of one of the plurality of predefined blade positions.
 11. The method of claim 9, wherein the position of the blade includes a cross-slope inclination.
 12. The method of claim 9, wherein the button is a first button, and the method further includes receiving a third operator input indicative of a desire to cause the cylinder to move the blade to a corresponding selected blade position via a second button.
 13. The method of claim 12, further including storing the target position of the blade as one of the plurality of predefined blade positions when the first operator input is received for a predetermined period of time.
 14. The method of claim 13, further including selecting one of the plurality of predefined blade positions when the second operator input is received for less than the predetermined period of time.
 15. The method of claim 12, further including receiving a fourth operator input indicative of a predetermined incremental adjustment of the position of the blade.
 16. A motor grader, comprising: a power source; at least one traction device; a frame; a drawbar-circle-moldboard supported by the frame; a blade pivotally connectable to the drawbar-circle-moldboard; a cylinder connecting the blade to the drawbar-circle-moldboard and configured to affect movement of the blade relative to the drawbar-circle-moldboard; a sensor configured to generate a signal indicative of a current position of the blade; a joystick having: a first button configured to: receive a first operator input indicative of a desire to store a target position of the blade as one of a plurality of predefined blade positions; and receive a second operator input indicative of a selection of one of the plurality of predefined blade positions; and a second button configured to receive a third operator input indicative of a desire to cause the cylinder to move the blade to a selected blade position corresponding with the selection; and a controller configured to selectively actuate the cylinder based on the first, second, and third operator inputs and the signal.
 17. The motor grader of claim 16, further including a display configured to display the plurality of predefined blade positions and illustrate the selection of one of the plurality of predefined blade positions.
 18. The motor grader of claim 16, wherein the position of the blade includes a cross-slope inclination.
 19. The motor grader of claim 16, wherein the controller is configured to store the target position of the blade as one of the plurality of predefined blade positions when the first button is engaged for a predetermined period of time.
 20. The motor grader of claim 19, wherein the controller is configured to select one of the plurality of predefined blade positions when the first button is engaged for less than the predetermined period of time. 